Understanding the human body is a team effort. That's where the Yachtel group comes in.

Researchers at Yachtolt have been delving into the secrets of probiotics for 90 years. Yacold also

partners with nature portfolio to advance gut microbiome science through the global grants for

gut health, an investigator-led research program. To learn more about Yachtold, visit yacult.co.

com.j.j. That's y-A-K-U-L-T.C-O.J-P. When it comes to a guide for your gut, count on Yacult.

For Scientific American Science quickly, I'm Rachel Feldman. Unless you're really on the low end of our listener

age bell curve, chances are you grew up learning about our solar systems nine planets. Of course,

unless you've been living under a rock since 2006, you also know that now we only have eight planets.

Sorry, Pluto fans. But maybe you've also heard rumblings

about the mysterious planet nine. This hypothetical extra planet has been popping in and out of the

news for more than a decade. Thanks to a new observatory set to come online in 2025,

the truth about Planet Nine could

finally be within reach. Here to tell us more is Claire Moskowitz, senior editor for Space

and Physics at Scientific American. Thanks so much for coming on to chat today.

Thank you for having me. So starting with basics, I feel like a lot of people have heard

vaguely of Planet 9. It's a very evocative concept. But when we talk about Planet 9, what are we

actually talking about? So we're talking about this potential planet. Nobody knows if it actually

exists or not that might live in our own solar system. So if you think about it,

it's a wild idea that there could be this whole other planet in our solar system that we've

never seen. You know, we obviously have these eight planets that we're really familiar with. Then,

of course, there's the contested situation with Pluto. So it's like, how could we

have missed a whole other world in our cosmic neighborhood? And we're not talking about something

...